Non-metallic knives hard to detect, experts say

Eric Malnic and Ricardo Alonso-ZaldivarSpecial to the Tribune

Airport security in the United States, strengthened to repel terrorists since last month, may still be no match for the Busse Stealth Hawk knife, marketed in a weapons catalog as "invisible to metal detectors."

The knife is among a class of composite and ceramic blades difficult or impossible to detect with current airport security equipment, according to security experts and knife manufacturers.

Such knives, sold openly and legally through retail stores, mail-order catalogs and on the Internet, expose a major loophole in the efforts to prevent a recurrence of the Sept. 11 terrorist hijackings, which apparently were executed with small box cutters and knives previously thought harmless.

Since the attacks, the Federal Aviation Administration has rescinded a rule allowing knives with blades shorter than 4 inches aboard flights. Now, "cutting instruments of any kind and composition," either carried by passengers or in their carry-on luggage, are prohibited.

But enforcing that new rule relies on equipment that is largely ineffective against non-metallic knives that are as sharp and as hard as steel. FAA officials acknowledge the system's vulnerability to plastic weapons but also insist security nevertheless is adequate.

Congressional and Bush administration officials have suggested that terrorists may have carried plastic weapons when they took over the four jetliners by attacking the flight crews, though whether they were using anything like the brawny Stealth Hawk is unknown.

The Stealth Hawk is made of a high-tech, non-metallic laminate known as MP45. Its 41/2-inch, serrated blade is so strong it can be "pounded through steel drums, car doors, wood planks etc. without damage," according to a catalog issued by Shomer-Tec, a mail-order company in Bellingham, Wash.

The purchase and possession of the Stealth Hawk and other similar "undetectable" knives are legal in most states.

No license, special permit or identification is needed to purchase one. To get a Stealth Hawk, a customer need only mail off a check for $137, plus a $7 handling fee, and Shomer-Tec will ship it via United Parcel Service.

"There is no place in our society for a weapon like this," said Jim Hall, former chairman of the National Transportation Safety Board. "Shame on the person who is marketing this. He puts all of us at risk."

Rep. John Mica (R-Fla.), chairman of a House subcommittee on aviation, said last week that the hijackers "may have been armed with hardened plastic knives in addition to the box cutters reported by a passenger on one of the planes."

A spokesman for Mica said his remarks were "based on information provided in a briefing by the administration."

Three weeks earlier, Transportation Secretary Norman Mineta said: "For the first time, we had a commercial airliner turned into a lethal weapon. People boarded with plastic knives that can be as sharp as metal knives." Mineta subsequently has declined to comment further on the subject.

Plastic weapons represent a tough challenge to existing security. Two electronic devices currently are used at airports to screen passengers: a metal detector and an X-ray machine.

FAA spokeswoman Rebecca Trexler acknowledged this week that existing metal detectors are not effective against plastic weapons. However, she said that such knives in carry-on baggage could be detected by airport X-ray screeners, who "are trained to detect all sorts of guns, knives and explosives."

Trexler said that FAA Administrator Jane Garvey "believes we have adequate security in place right now, given the heightened threats, but we will be looking at systems constantly to see how they might be improved."

Trexler said one of these is a "back-scatter" probe that uses harmless, low-level radiation to paint a detailed picture of what a passenger might be carrying beneath clothing.

Eric Malnic and Ricardo Alonso-Zaldivar are staff reporters for the Los Angeles Times, a Tribune newspaper